Tanpopo (Dandelion in Japanese) is superhumanly intelligent and inhumanly emotionless. Attached to a mysterious machine, she is ruled by her mind and vast knowledge. One day, her heart rises up to struggle against the ruling mind. Torn and confused, she now seeks her humanity, longing to feel what other humans feel.
Kuro, disguising himself as The Poodle, hears her lamentations. He promises Tanpopo that she can experience all human emotions, especially love and happiness. Alas, this kind of offer doesn't come without a price…Kuro is The Devil in disguise and he is after Tanpopo's Soul.
The series follows Tanpopo's journey into the human world, as she is confronted with the reality of life and emotion. As she goes out into the world, she will meet a variety of characters and be plunged into challenging situations. Will she be able to quiet her highly analytical mind and allow her heart to come to life? Will she be able to accept and embrace the emotions that are rising up within her? Will her quest for love set her free or will it shackle her for eternity?
Kuro, devilishly cute and childishly playful, has a series of surprises in store for Tanpopo, as he changes forms and creates situations that elicit emotional responses in the girl. Through his trickery, he undergoes various transformations including his boy "Kuro" form, Specter and various other characters.